Effect of abiotic stresses on bioactive contents of vegetables and high-pressure technology in related functional beverages

[SPA] Los compuestos fenólicos son fitoquímicos con propiedades beneficiosas para la salud, presentes en gran medida en las frutas y verduras, como la zanahoria o el brócoli. La zanahoria es una verdura ampliamente consumida en todo el mundo. Sin embargo, su contenido fenólico es relativamente bajo en comparación a otras verduras. Consecuentemente, el aumento de los niveles de compuestos fenólicos en zanahorias, usando estreses abióticos, por ejemplo, podría agregar un valor añadido a esta verdura para las industrias alimentaria y farmacéutica. El ácido clorogénico representó el 70 % de la suma de los compuestos fenólicos en las zanahorias estudiadas. Los compuestos fenólicos totales (TPC en inglés) estuvieron altamente correlacionados con la capacidad antioxidante total (TAC en inglés) con un R2=0,82. Se comprobó que los estreses abióticos, como el cortado y la conservación en atmósfera de alto oxígeno (80 kPa O2), indujeron un elevado aumento de la enzima fenilalanina amonio liasa (PAL en inglés), TPC y TAC en zanahorias durante una conservación a 15 ºC durante 72 h. Aunque el pretratamiento de la zanahoria rallada con una dosis intermedia (9 kJ m-2) de radiación UV-C redujo la acumulación de compuestos fenólicos, se registró un incremento del 600 % en estas muestras almacenadas en alto oxígeno durante 72 h. Las primeras conclusiones de esta tesis doctoral, resultan útiles para las industrias farmacéutica y alimentaria, por obtener una gran fuente de compuestos bioactivos de esta verdura, y probablemente, aplicable en otros productos vegetales A continuación, se estudió el efecto de pretratamientos con radiación UV-B (1,5 kJ m-2) sobre los contenidos de PAL/TPC/TAC en zanahoria rallada y su combinación con una dosis bajo-intermedia (4 kJ m-2) de radiación UV-C. El pretratamiento con UV-B provocó el máximo aumento de PAL y TPC de 760 y 498 %, respectivamente, tras 72 h a 15 ºC, mientras que el tratamiento simple y combinado de UV-C indujo incrementos de un 440 %. Por consiguiente, el uso de UV-C, de alto interés como tratamiento sanitizante alternativo al cloro, combinado con la radiación UV-B no afectó negativamente la acumulación de compuestos bioactivos, consiguiendo aumentos similares a las muestras control (no tratadas). El cultivo del brócoli conlleva la producción de altas cantidades de subproductos, con el consiguiente impacto medioambiental, los cuales podrían ser usados como fuentes de compuestos beneficiosos para la salud por las industrias de alimentación y farmacéuticas. Además, estos subproductos de brócoli podrían ser revalorizados mediante el incremento de sus compuestos beneficiosos para la salud mediante radiación UV como estrés abiótico. En esta línea, se estudiaron los efectos de diferentes tratamientos de radiación UV-B (5, 10 and 15 kJ m-2), individual o combinados con una dosis de UV-C (9 kJ m-2), sobre los principales compuestos bioactivos de los subproductos del brócoli Bimi® (hojas y tallos) siendo comparados con las partes comestibles de este vegetal, los floretes. Las hojas mostraron TPC y TAC similares a los de los floretes con niveles de 1716 y 552 mg kg-1, respectivamente. Además, las hojas mostraron contenidos de glucorafanina/glucobrasicina 2,5/14,5 mayores que los floretes. Los tratamientos de UV incrementaron inicialmente los niveles de TPC y TAC de las muestras en un 30-97 y 20-424 %, respectivamente. Particularmente, el tratamiento UVB10+C indujo los mayores incrementos (110 %) de TPC en las hojas de Bimi® en las últimas 48 h de conservación mientras que UVB10 y UV10+C conllevaron a los niveles más altos de TPC (709 y 680 mg kg-1) en los tallos a las 48 h. Además, el tratamiento UV10+C indujo los mayores incrementos de glucobrasicina del 34 % mientras que UVB15 y UVB15+C produjeron los contenidos más altos de glucorafanina (131 y 117 mg kg-1) en los floretes después de 72 h. De esta forma, las hojas del brócoli Bimi® se muestran como un subproducto que puede ser utilizado como una fuente excelente de glucosinolatos y compuestos fenólicos (con alto poder antioxidante) para las industrias alimentarias y farmacéuticas. Además, el uso de tratamientos UV-B/C postcosecha combinados pueden revalorizar en gran medida estos subproductos agrícolas y también añadir valor a los floretes comestibles mínimamente procesados en fresco del brócoli Bimi®. Se estudió la calidad de un batido (smoothie) funcional obtenido de zanahoria rallada, previamente estresada (UV-C y/o alto oxígeno), tratado térmicamente (90 ºC durante 30 s), durante 14 días a 5 ºC. El smoothie tratado térmicamente mostró una buena calidad fisicoquímica y microbiológica (< 6 log unidades formadoras de colonias (CFU en inglés) g-1), tras los 14 días a 5 ºC. Sin embargo, en los smoothies que contenían zanahoria no irradiada se registraron recuentos más bajos de psicrófilos, mohos y levaduras. Los smoothies tratados térmicamente con zanahoria rallada no irradiada y almacenada en alto oxígeno mostraron los contenidos más altos de TPC con 13.8 mg de ácido clorogénico kg-1 tras 14 días at 5 ºC. En ese aspecto, la incubación previa de la zanahoria rallada en condiciones de hiperoxia permitió obtener un smoothie funcional con alto contenido de compuestos fenólicos, así como una buena calidad microbiológica y fisicoquímica tras 14 días a 5 ºC. La pasteurización fría de alimentos, como el procesado con alta presión (HPP en inglés), permite conseguir un producto con una mejor calidad nutricional, sin perder sus propiedades sensoriales, logrando también una vida útil más larga comparado con los tratamientos térmicos convencionales. De esta forma, se estudió la calidad fisicoquímica y microbiológica, y PAL/TPC de un smoothie naranja (con zanahoria y calabaza) tras diferentes tratamientos de HPP (control, 300-600 MPa durante 5 min a 23 ºC) y durante su conservación de 7 días a 5 ºC. En general, los parámetros de calidad no se vieron afectados por los tratamientos de HPP en comparación al control en el día de procesado ni tras 7 días a 5 ºC. HPP redujo los recuentos iniciales de mesófilos (3,4 log CFU mL-1) a 2,0-2,7 unidades logarítmicas, manteniéndolas durante los 7 días a 5 ºC, a diferencia de las muestras control. Los parámetros de calidad fisicoquímica de las muestras tratadas con HPP se mantuvieron durante la conservación. En general, los tratamientos de 300 y 600 MPa provocaron una mayor actividad de PAL tras 7 días a 5 ºC. Los TPC de los smoothies tratados con 300 y 400 MPa mostraron los mayores incrementos (1,6 veces) tras la conservación. La actividad de muchas enzimas alterantes de la calidad del producto puede aumentar debido a tratamientos de HPP de intensidad baja-intermedia en muchas bebidas. Por esta razón, en el siguiente experimento se contrarrestaron estos efectos debidos al HPP mediante la encapsulación con maltosil-β-ciclodextrina (90 mM) usando como modelo zumos de manzana debido a su rápido pardeamiento enzimático durante el procesado. La degradación del color del zumo de manzana durante 60 min a 22 ºC fue ajustada muy bien mediante un modelo de conversión fraccional con la raíz del error cuadrático medio (RMSE en inglés) inferior a 1,3. Los tratamientos de HPP (300-600 MPa durante 5 min a 22 ºC) no afectaron el efecto antipardeante de la maltosil-β-ciclodextrina. Por esta razón, la adición de maltosil-β-ciclodextrina en zumo de manzana, antes del tratamiento bajo-moderado de HPP (300 MPa durante 5 min a 22 ºC) puede controlar en gran medida el pardeamiento enzimático. En esta Tesis doctoral también se desarrolló por primera vez el concepto “listo para licuar” (ready-to-blend en inglés). De esta forma, se estudió la evolución de los parámetros de calidad de una mezcla de ensalada de cuarta gama de frutas y verduras ready-to-blend durante su conservación a 5 ºC. La vida útil del producto se extendió hasta 9 días mediante una película comestible de quitosano (10 g L-1) donde la actividad de la polifenoloxidasa y los niveles microbiológicos fueron muy bien controlados. Paralelamente se aumentó el valor añadido del producto mediante la fortificación con vitamina B12 (8.6 μg kg-1). Esta vitamina es de gran interés para diversos sectores de la población, tales como vegetarianos/veganos, personas mayores etc., debido a las necesidades especiales de la misma. El smoothie preparado posteriormente de la mezcla ready-to-blend mostró en general una buena calidad durante su conservación a 5 ºC durante 48 h. [ENG] Phenolic compounds are phytochemicals with high health-promoting properties which are present in several fruit and vegetables such as carrots and broccoli. Carrot is a worldwide highly consumed vegetable although its phenolic content is relatively low regarding other horticultural products. Accordingly, the enhancement of phenolic levels in carrots, using i.e. abiotic stresses, will add value to this popular vegetable for the food and pharmaceutical industries. Chlorogenic acid represented 70 % of the sum of phenolic compounds in carrots. Total phenolic contents (TPC) of carrots during storage periods were highly correlated (R2=0.82) to total antioxidant capacity (TAC) of these samples. It was found that shredding (wounding stress) and hyperoxia storage (80 kPa O2) induced the highest phenylalanine ammonia-lyase (PAL), TPC and TAC enhancements in carrots during storage at 15 ºC for 72 h. Although pretreatment of shreds with an intermediate UV-C dose (9 kJ m-2) reduced phenolic accumulation, 600 % increments were still registered in those samples stored under hyperoxia conditions for 72 h. These first findings of the PhD Thesis supply to the food and pharmaceutical industries useful and sustainable tools to obtain a great source of health-promoting compounds from this vegetable, and probable to others. Subsequently, the effect of UV-B pretreatment (1.5 kJ m-2) was studied on the PAL/TPC/TAC of shredded carrots and its combination with a low-intermediate (4 kJ m-2) UV-C dose. UV-B treatment induced the highest PAL/TPC of 760/498 % after 72 h at 15 ºC, regarding their initial levels, while single and combined UV-C treatments induced a TPC accumulation of 440 %. Accordingly, the use of UV-C treatment, with high sanitizing interest for the fresh-cut industry, combined with UV-B radiation did not negatively affect the accumulation of bioactive compounds, achieving similar enhancements to untreated samples. Broccoli cultivation leads to high volumes of plant by-products with high environmental impact which may be instead used as sources of health-promoting compounds for the food and pharmaceutical industries. Furthermore, such broccoli by-products may be revalorized through the increase of their health-promoting compounds with postharvest UV radiation as an abiotic stress. Accordingly, the effects of different postharvest UV-B radiation doses (5, 10 and 15 kJ m-2), single or combined with UV-C treatment (9 kJ m- 2), were studied on the main bioactive compounds of Bimi® broccoli by-products (leaves and stalks) being compared to Bimi® edible florets. Leaves showed similar TPC and TAC, with 1716 and 552 mg kg-1 respectively, compared to florets. Furthermore, leaves showed 2.5/14.5 higher glucoraphanin/glucobrassicin contents than florets. UV postharvest treatments initially increased TPC and TAC levels of samples by 30-97 and 20-424 %, respectively. Particularly, UVB10+C treatment induced the highest TPC increase (110 %) in Bimi® leaves in the last 48 h of storage while UVB10 and UV10+C led to the highest TPC (709 and 680 mg kg-1) of stalks at 48 h. Furthermore, UV10+C treatment increased glucobrassicin levels of leaves by 34 % while UVB15 and UVB15+C induced the highest glucoraphanin levels (131 and 117 mg kg-1) in florets after 72 h. Accordingly, Bimi® leaves are hereby presented as a by-product that may be used as an excellent source of glucosinolates and phenolics, with high total antioxidant capacity, for the food and pharmaceutical industries. In addition, postharvest intermediate-high UV-B/C combined radiation treatments can highly revalorize such agricultural by-products and also add value to the edible fresh-cut Bimi® florets. A functional smoothie containing the previously stressed (UV-C and/or high O2) carrot shreds with high TPC/TAC contents was thermally treated (90 ºC for 30 s) and the beverage quality was studied during 14 days at 5 ºC being compared to CTRL samples. Heat-treated smoothies showed a good physicochemical and microbiological quality (< 6 log CFU g-1) after 14 days at 5 ºC, although smoothies containing non-irradiated shreds registered lower psychrophilic and yeasts and moulds levels. Heat-treated smoothie containing non-irradiated O2-shreds showed the highest TPC of 13.8 mg kg-1 after 14 days at 5 ºC. In this sense, a pre-enrichment incubation of carrot shreds under hyperoxia conditions allowed to obtain a functional smoothie with high phenolic levels and good microbiological and physicochemical quality up to 14 days at 5 ºC. A non-thermal treatment, such as high pressure processing (HPP), of beverages may allow to obtain a product with better bioactive/nutritional and sensory quality, and extended shelf life regarding thermally treated samples. Accordingly, the physicochemical and microbial quality, and PAL/TPC of an orange smoothie (carrot and pumpkin) after different HPP treatments (CTRL, 300-600 MPa for 5 min at 23 ºC) and during storage for 7 days at 5ºC were studied. In general, quality parameters did not highly change after HPP treatments compared to CTRL samples on the processing day and after 7 days at 5 ºC. HPP reduced initial mesophilic counts (3.4 log CFU mL-1) by 2.0-2.7 log units being these microbial counts well maintained after 7 days at 5 ºC contrary to CTRL samples. The physicochemical quality of the HPP-treated smoothies was highly maintained during storage. Generally, the 300 and 600 MPa HPP treatments induced the highest PAL activities after 7 days at 5 ºC. The initial TPC (712.1 mg ChAE kg-1) was increased in the smoothies reaching the 300 and 400 MPa-treated samples the highest increments (1.6-fold) after storage. The activity of some quality-degradative enzymes may be increased in determined beverages under low-moderate HPP treatments. For that reason, in the next study we tried to palliate such undesirable HPP effects by encapsulation with maltosyl-β-cyclodextrin (90 mM) using apple juice as beverage model due to the rapid enzymatic browning during processing of this fruit juice. Colour degradation of apple juice during 60 min at 22 ºC was well fitted to a fractional conversion model with root-mean-square error (RMSE) < 1.3. HPP treatments (300-600 MPa for 5 min at 22 ºC) did not affect the antibrowning effect of maltosyl-β-cyclodextrin. In that sense, maltosyl-β-cyclodextrin addition to apple juice prior to a low-moderate HPP treatment (300 MPa for 5 min at 22 ºC) highly controlled enzymatic browning. A new food concept ‘ready-to-blend’ was firstly developed and studied in this PhD Thesis. Accordingly, the quality of a fresh-cut fruit/vegetables ‘ready-to-blend’ product was studied during storage at 5 ºC. The shelf life of the ready-to-blend product was highly extended to 9 days by a chitosan coating (10 g L-1) being microbial levels and polyphenoloxidase activity well controlled. Added value of the product was enhanced by fortification with vitamin B12 (8.6 μg kg-1) being of high interest for specific population sectors, such as vegetarians/vegans, elderly, etc., which have special needs for this vitamin. The prepared smoothies from the ready-to-blend portion showed a good quality during subsequent storage for 48 h at 5 ºC.Escuela Internacional de DoctoradoUniversidad Politécnica de CartagenaPrograma de Doctorado Técnicas Avanzadas en Investigación y Desarrollo Agrario y Alimentari

Abiotic stress combination to improve healthiness of fresh vegetables smoothies

Several epidemiological studies have revealed the potential benefits of an appropriate and equilibrated diet rich in fruit and vegetables to prevent several diseases in those people with genetic predisposition. Phytochemicals of vegetables, such as phenolic compounds, carotenoids and vitamins offer health-promoting benefits. Orange vegetables, such as carrots, pumpkin, sweet potatoes, etc., are very popular in the Mediterranean diet. These vegetables are important contributors of antioxidants in the diet as polyphenols, carotenoids and vitamins (A, C, E, etc). Accordingly, these vegetables could be used as a functional food if the content of such phytochemicals is enhanced. Abiotic stresses, such as UV-C, superatmospheric oxygen, wounding, etc., applied during postharvest can be used as a tool to enhance phytochemicals. Hence, these stressed vegetables with high health-promoting properties can be consumed as a functional food, with high added value, or as a natural nutraceutical to be included in other functional foods like beverages like smoothies.We acknowledge Spanish Ministry of Economy and competitiveness MINECO (AGL2013-48830-C2-1-R) and FEDER for financial support

Health-promoting compounds and quality changes of a functional carrot smoothie during shelf life

[SPA] Las zanahorias son la sexta verdura más consumida. Sin embargo, el contenido de los compuestos bioactivos fenólicos de las zanahorias no es muy alto. Los fenoles/antioxidantes de zanahorias pueden ser enormemente incrementados mediante diferentes estreses abióticos postcosecha. De esta forma, se preparó un smoothie funcional de zanahorias con altos niveles de fenoles/ antioxidantes y se estudiaron los cambios en su calidad bioactiva/fisicoquímica tras 25 días a 5 °C. Los compuestos fenólicos en los smoothies de zanahorias preincubadas en hiperoxia se incrementaron hasta un 1000% tras la conservación, aunque otros compuestos antioxidantes se redujeron en un 44%. [ENG] Carrots occupy the sixth place among the list of most consumed vegetables, although the content of the bioactive compounds phenolic acids is almost the lowest one. The phenolic/antioxidant levels of carrots may be greatly enhanced with a pre-enrichment incubation with different postharvest abiotic stresses. Accordingly, a functional carrot smoothie with phenolic /antioxidant-enriched levels was produced and its bioactive/physicochemical quality was monitored after 25 days at 5 °C. The total phenolics content from hyperoxia-preincubated carrot shreds was incremented up to 1000% after storage although other antioxidants compounds were reduced by 44%.Los autores agradecen al Ministerio de Economía y Competitividad Proyecto MINECO AGL2013-48830-C2-1-R la financiación recibida para este trabajo

Novel functionalised imidazo-benzocrown ethers bearing a thiophene spacer as fluorimetric chemosensors for metal ion detection

Novel phenylalanine derivatives bearing benzimidazole and crown ethers as coordinating/reporting units and thiophene as a spacer unit were synthesized for the first time, and their evaluation as fluorimetric chemosensors was carried out in acetonitrile and acetonitrile/water solutions. 15-Crown-5 benzimidazolyl phenylalanine methyl ester, 15-crown-5 thienylbenzimidazolyl phenylalanine methyl ester and 18-crown-6 thienylbenzimidazolyl phenylalanine methyl ester were tested for alkaline, alkaline-earth and transition metal ions (such as Na+, Ca2+, Cd2+, Co2+, Cr3+, Cu2+, Fe2+, Fe3+, Hg2+, Ni2+, Pd2+ and Zn2+). The different crown ether binding moieties as well as the electronic nature and the length of the π-bridge linked to the benzimidazole heterocycle allowed the fine tuning of the sensory properties as seen by spectrofluorimetric titrations. Therefore, 15-crown-5 benzimidazolyl phenylalanine methyl ester is a fluorimetric chemosensor, being selective and sensitive for Cu2+ and Pd2+ in aqueous solutions (ACN/H2O; 80:20). On the other hand, the metal cation sensing properties displayed by 15-crown-5 thienylbenzimidazolyl phenylalanine methyl ester bearing an arylthienyl spacer showed that this is a promising candidate as fluorimetric chemosensor for Fe3+, Pb2+ and Pd2+ in acetonitrile solution.Thanks are due to Fundação para a Ciência e Tecnologia (Portugal) for financial support to the Portuguese NMR network (PTNMR, Bruker Avance III 400-Univ. Minho), FCT and FEDER (European Fund for Regional Development)-COMPETEQREN-EU for financial support to the research centre CQ/UM [PEst-C/QUI/UI0686/2013 (FCOMP-01-0124-FEDER-037302], a PhD grant to C.I.C. Esteves (SFRH/BD/68360/2010) and a post-doctoral grant to R.M.F. Batista (SFRH/BPD/79333/2011).info:eu-repo/semantics/publishedVersio

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011